Antisense RNA that affects Rhodopseudomonas palustris quorum-sensing signal receptor expression
Antisense RNA that affects Rhodopseudomonas palustris quorum-sensing signal receptor expression
复制标题
DOI：
10.1073/pnas.1200243109
复制
发表时间：
2012-07
期刊：
影响因子：
--
通讯作者：
Hidetada Hirakawa;C. Harwood;Kieran B. Pechter;A. Schaefer;E. Greenberg
中科院分区：
文献类型：
--
作者：
Hidetada Hirakawa;C. Harwood;Kieran B. Pechter;A. Schaefer;E. Greenberg
在细菌Rhodopyramidpalustris中的群体感应涉及RpaI信号合酶，其产生p-香豆酰-高丝氨酸内酯（pC-HSL）和RpaR，其是pC-HSL依赖性转录激活因子。还有一种功能未知的反义rpaR转录物（asrpaR）。最近的RNAseq研究表明，细菌反义RNA是丰富的，但对这些分子的功能知之甚少。因为asrpaR的表达是群体感应依赖的，我们试图表征其生产和功能。我们表明，asrpaR是大约300-600个碱基，并产生响应pC-HSL和RpaR。在距离asrpaR转录起始位点51.5bp处有一个RpaR结合位点。我们发现，asrpaR过表达降低RpaR水平，rpaI表达，和pC-HSL生产。我们还产生了一个asrpaR突变体，它显示出升高的RpaR水平和升高的rpaI表达。因此，asrpaR抑制rpaR翻译，这种抑制导致RpaR依赖性rpaI表达的抑制，从而抑制pC-HSL的产生。中华民国palustris asrpaR代表一种反义RNA，其活性可以被测量，并且其与功能相关的独特调节回路被阐明。它也代表了酰基高丝氨酸内酯群体感应信号响应转录因子的另一个微妙的调节层。
Quorum sensing in the bacterium Rhodopseudomonas palustris involves the RpaI signal synthase, which produces p-coumaroyl-homoserine lactone (pC-HSL) and RpaR, which is a pC-HSL–dependent transcriptional activator. There is also an antisense rpaR transcript (asrpaR) of unknown function. Recent RNAseq studies have revealed that bacterial antisense RNAs are abundant, but little is known about the function of these molecules. Because asrpaR expression is quorum sensing dependent, we sought to characterize its production and function. We show that asrpaR is approximately 300–600 bases and is produced in response to pC-HSL and RpaR. There is an RpaR-binding site centered 51.5 bp from the mapped asrpaR transcript start site. We show that asrpaR overexpression reduces RpaR levels, rpaI expression, and pC-HSL production. We also generated an asrpaR mutant, which shows elevated RpaR levels, and elevated rpaI expression. Thus, asrpaR inhibits rpaR translation, and this inhibition results in suppression of RpaR-dependent rpaI expression and, thus, pC-HSL production. The R. palustris asrpaR represents an antisense RNA for which an activity can be measured and for which a distinct regulatory circuit related to a function is elucidated. It also represents yet another subtle regulatory layer for acyl-homoserine lactone quorum-sensing signal-responsive transcription factors.